Dental matrix retainer



April 4, 195o Filed Jan. 14. 1947 I. INVENTOR.

B. r--Q Tor-'FLEMIRE K, DENTAL MATRIX RETAINER 2 Sheets-Sheet 1 l E* BENJAMIN RTOFFLEMIRE Waff, MA/Vhww-c AT TORNEYS A121414, 1950 B. F. TOFFLEMIRE 2,502,903

` DENTAL MATRIX RETAINER Filed Jan. 14, 1947 .2 Sheets-Sheet 2 7mm,... agrw TORNEYS Patented Apr. 4, 1950 UNITED STATES PATENT oFEicE DENTAL MATRIX RETAINER Benjamin F. Tomemire, Lafayette, Calif. Application Januar! 14, 1947, Serial No. 721,995

5 claims. (ci. sa-ss) The present invention relates to improvements in a dental matrix retainer, embodying new features over the retainers disclosed in my copending application, Serial No. 677,577, filed in the United States Patent Oiilce on June 18, 1946, now Patent No. 2,439,703. The invention pertains to the combinations. constructions and arrangement of parts as hereinafter described and claimed. l

In my copending application above mentioned, I show matrix retainers that are especially adapted to hold a dental matrix band about a tooth. The retainers therein shown permit a dentist to easily and quickly adapt a matrix about a prepared cavity, or cavities, in such a manner that the natural contours of the tooth will be restored. These retainers were designed so that they could be readily and safely disengaged from the matrix, and the latter removed from a freshly packed restoration without prejudice to the contact point, or points, and without distortion of the marginal ridges.

The copending case further illustrates a control spindle and a rotatable sleeve, both extending outside the oral cavity where the dentist can have a clear field of vision for manipulating the device without the necessity of reaching into the mouth. The spindle clamps the ends of a matrix to a sliding block, while the sleeve is operable to move the block along a frame to draw the matrix around the tooth being treated, or to release the matrix.

It is proposedin the present invention to provide an improved matrix retainer frame that will permit wedges to be driven between adjacent teeth for spreading the latter and at the same time to allow unobstructed functioning of the retainer. Further improvements have been made in the sliding block and the means for mounting the block on the frame of the matrix retainer.

Another object is to provide a simplified form of a matrix retainer, as compared with the retainers covered in my copending application, thus reducing the cost of manufacture. The frame of the retainer is opened along one side thereof. which facilitates the insertion of the matrix ends into the retainer or removal therefrom.

Other objects and advantages will appear as the specification continues. and the novel features will be set forth in the claims hereunto appended.

For a better understanding of my invention, reference should be had to the accompanying drawings, forming part ofthis application, in u which:

2 Figure .1 is anA isometric view of the retainer applied to a matrix, the latter encircling a tooth: Figure 2 is a vertical transverse sectional vic' taken along the line II-II of Figure l;

Figure 3 is a view of the clamping spindle; Figure 4 is a top plan view of the retainer having a matrix clamped therein, parts being l shown in section;

Figure 5 is a side elevation of the matrix retainer;

Figure 6 is a side elevation of the spindle-receiving sleeve;

Figures '1, 8 and 9 are isometric views of the matrix retainer frame, matrix-clamping block, and block-mounting strap, respectively;

Figure 10 is an elevation from the buccal aspect showing the matrix encircling a tooth;

Figure 11 is an isometric view of the matrix ready to be applied to a tooth; and

Figure 12 is a plan view of a diagonally-folded band from which the matrix is formed.

While I have shown only the preferred form of my invention, it should be understood that various changes, or modications, may be made within the scope of the annexed claims without departing from the spirit thereof.

In carrying my invention into practice, I provide a matrix retainer indicated generally at A. which is designed for holding a matrix B in encircling relation wth a tooth C during restoration of the latter. Before proceeding with the details of the retainer, I shall describe the matrix and the manner in which it is fashioned.

The matrix B is formed from a strip l of dental matrix band material by a former and cutter disclosed in my copending application, Serial No. 674,354, filed on June 4, 1946, now Patent No. 2,466,830. The strip is folded diagonally intermediate of its length, as at 2 (see Figure 12) to present two end sections 3, which are arranged in diverging relation with one another when the strip is ilat. The ends of the strip are brought together, as in Figure 11, and the fold causes the matrix to be conical in shape.

Referring to Figure l, I show the tooth C as being the right lower first molar and situated between the second bicuspid D and the second molar E. The matrix B encircles the tooth C and the ends 3 extend from the central portion of the buccal aspect 4, with the fold 2 arranged on the lingual side 5 of the molar. The lling 6 is indicated as extending from the mesial aspect 1, across the occlusal surface 8, and down the distal aspect 9.

The matrix extends well down toward the gingival border I0 so as to prevent any gingival overhanging of the metal masses. The conical shape of the matrix assures that the filling will restore the natural contour of the tooth. The matrix may be tightened in the manner hereinafter described to insure peripheral adaption, and grip of the retainer on the matrix at the gingival margin permits thorough and adequate condensation of the filling material without any of this material being forced out beneath the gingival peripheral border.

The matrix retainer A has a frame F of the shape shown in Figures 1 and '1, and includes a longitudinally-extending bar Il on which a matrix-clamping block G is slidably mounted. This block is fashioned with a guideway I2 adapted to receive the bar Il (see Figure 2). A channelshaped block-mounting strap Il has its web Ila bearing against the bar li, while the flanges I 4b thereof are fastened to the top and bottom of the block by set-screws il, or other suitable means. 'Ihe bar Il has a head F' thereon, which denes four parallel and spaced-apart fingers Il. It, l1 and I8. This head is substantially U- shaped when viewed from the front thereof, as in Figure 5. The length of the fingers are greater than the height of the bar Il. This arrangement permits a wedge I9 to be driven between the tooth receiving the matrix and an adjacent tooth for separating them, as indicated in Figure 1, and at the same time allowing the ngers to maintain their grip on the matrix.

The retainer is designed to hold a matrix that encircles any tooth in the arch. The end sections 3 may be received in the slots defined between the fingers iS-Il. or l6-I8, so that the matrix loop will project laterally from the retainer on the desired side thereof, as shown in Figure 4. Also, the end sections 3 may extend through the slot disposed between the fingers i5 and i6. and thus the loop of the matrix will be positioned directly in front of the retainer. The

Ihe sleeve has an annular groove 21 therein for receiving the forks 2l of a U-shaped end Il" fashioned on the matrix frame. This U end extends at right angles relative to the fingers on the head F'. One side of this U has an unthreaded opening 29 through which the spindle 23 extends with freedom of rotation.

The sleeve J may be rotated in one direction to advance the block G toward the head F',while a rotation of the sleeve in the opposite direction will retract the block. The end F" holds the sleeve against longitudinal movement, but permits its free rotation.

Having thus described the various parts of my matrix retainer, the operation thereof may be summarized as follows:

Assuming vthai; the matrix B has been preshaped into substantially the outline shown in Figure 11 and the dentist desires to apply the matrix to the right lower first molar C, the sleeve J is rotated so as to move the block G toward the head F. Next the matrix ends 3 are inserted into the slots provided between the fingers I5|1 and |1-I8 and depressed into the diagonal slot 20 in the block G. The side of the frame F opposite the bar il is opened, and this facilitates insertion of the matrix into the retainer. The lmob 25 is actuated for bringing the conical vtip 24 of the spindle H into clamping relation with the matrix ends 3.

Now the loop of the matrix is arranged around the tooth with the fold 2 thereof positioned on the lingual side. The matrix is pressed down until it is disposed close to the gingival border. The dentist rotates the sleeve J to retract the block G relative to the head F' until the matrix is drawn tightly around the tooth. A wedge I8 may be inserted between the tooth being treated l and an adJacent tooth to separate them and particular slot selected in the head depends upon the position that best ts the need of the dentist for the tooth being treated.

The matrix-clamping block G has a diagonally-extending slot 20 to receive the end sections 3 of the matrix strip. It will be noted that the top flange Hb of the strap Il has an angular edge 2i that registers with the side 20a of the slot 20.

4The edge 2| serves as alimit stop against which the end sections 3 of the matrix may be positioned so as to align them with the slot 20. Thereafter, the end sections may be pressed downwardly into the slot 20.

In Figures 4 and 8, I show the block G as having a longitudinally-extending threaded bore 22, which intersects the diagonal slot 20. A spindle indicated generally at H has a threaded portion 2l that is received in the bore 22. and the spindle has a conical end 2| with a surface that parallels the slot 20. The spindle may be rotated in the bore 22 by an operating knob 25 to cause the conical head to clamp the ends 3 of the matrix in the block G. Now a movement of the block along the bar l I will move the matrix ends therewith. When the block is moved to the right in Figure l, the matrix will be drawn tightly upon the tooth C, while movement to the left will relax the grip of the matrix upon the tooth.

The means for moving the spindle axially after` it has clamped the matrix ends l to the block G comprises a sleeve J. The latter has a spindlereceiving bore 26. with a threaded portion 26a thus allow the matrix to be easily applied. The retainer may be inverted, if desired. The height of the bar I l is less than the length of the ilngers i5 to I8, inclusive, and thus will permit the matrix to be lowered on the tooth the proper amount and still allow the wedge to be utilized.

The sleeve J and knob 25 project beyond the patlents mouth so that the dentist may operate either without inserting his tlngers into the mouth of the patient. A clear view of the tooth is assured and the dentist can observe the matrix as it is tightened or loosened.

To free the retainer from the matrix, the knob 25 is turned while holding the sleeve J against rotation. This backs the conical end 24 of the spindle H from the ends l of the matrix. The head F now may be freedfrom the matrix and the latter removed from the tooth. The manipulations of the knob 25 and sleeve J are accomplished outside the oral cavity. This is of the greatest possible convenience and comfort to the patient.

The inverted-conci principle of the specially formed matrix actually results in a more positive gingival grip of the matrix about the tooth as the filling material is condensed into the cavity. The resulting occlusal-ilare" permits the dentist to build the filling out as snugly as he wishes to condense the filling material against the adjacent tooth. The device lends itself admirably to the mechanical separation of the teeth where this is necessary.

The matrix may be removed from` the tooth in one piece. In case of unusually tight contact points, the matrix may be severed. at the narfor receiving the threaded spindle (see Figure 4). u rowed lingual fold 2 and the mesial and distal halves gently rotated lingually and toward the gingival oor. This actually tends to seat the lling more firmly during the removal of the matrix.

The size of the conical loop of the matrix can be controlled and the fold 2 maintained on the lingual aspect during the adjustment, since either end of the matrix can be moved with respect to the other by merely loosening the spindle H and readjusting the matrix ends. The width of the strip from which the matrix is formed may be changed in accordance with the requirements. In this connection, it will be noted that the slots defined by the fingers I6 to I8, inclusive, and the slot 20 all open in the same direction. Accordingly, a wider or narrower strip of matrix material can be inserted thereinto.

The folded type of band shown in Figures 11 and 12, is particularly well suited for teeth having an exaggerated axial contour, such as bell-crowned, posterior adult teeth and deciduous molars. A curved type of band, not shown, is well suited for the average, moderately contoured posterior teeth, and a straight band, not shown, is applicable to all other teeth having moderately slight, or less than average contour.

I claim:

1. In a dental matrix retainer; a frame having a slotted head arranged for slidably-receiving overlapped strips of a matrix, with a loop on the latter extending beyond the head to encircle a tooth; the frame including a bar; a block fashioned with a guideway having the bar disposed therein; a channel-shaped strap having its web bearing against the bar and its anges overlying and being secured to the block; the block being formed with a diagonal slot for receiving the endportions of the matrix; means for clamping the end portions of the matrix in the slot of the block; and means projecting from the oral cavity of the patients mouth when the matrix encircles a tooth for advancing or retracting the block relative to the head; the clamping means also being operable from a position exterior of the patients mouth.

2. In a dental matrix retainer; a frame having a slotted head arranged for slidably-receiving overlapped strips of a matrix, vwith a loop on the latter extending beyond the head to encircle a tooth; the frame including a bar; a block fashioned with a guideway having the bar disposed therein; a channel-shaped strap having its web bearing against the bar and its ilanges overlying and being secured to the block; the block being formed with a diagonal slot for receiving the end portions of the matrix; means for clamping the end portions of the matrix in the slot of the block; and means projecting from the oral cavity of the patients mouth when the matrix encircles a tooth for advancing or retracting the block relative to the head; the clamping means also being operable from a position exterior of the patients mouth; one ange of the strap having an angular edge registering with one side of the diagonal slot in the block, and arranged to serve as a stop against which the end portions of the matrix may be abutted prior to inserting them into the diagonal slot.

3. In a dental matrix retainer; a frame having a slotted head arranged for slidably-receiving overlapped strips of a matrix, with a loop on the latter extending beyond the head to encircle a tooth; the frame including a bar; a block slidably disposed on the bar and having a diagonal slot for receiving end portions of the matrix; the slot being disposed to one side of the bar, and that side of the frame being entirely open to facilitate edgewise insertion of the matrix ends into 5 the slot of the block; means for clamping the end portions of the matrix in the block slot; and means projecting from the oral cavity of the patients mouth when the matrix encircles a tooth for advancing or retracting the block relative to the head; the clamping means also being operable from a position exterior of the patients mouth. v

4. In a dental matrix retainer; a frame having a slotted head arranged for slidably-receiving overlapped strips of a matrix, with a loop on the latter extending beyond the head to encircle a tooth; the frame including a bar; a block slidably disposed on the bar and having a diagonal slot for receiving end portions of the matrix; the slot being disposed to one side of the bar, and that side of the frame being entirely open to facilitate edgewise insertion of theu matrix ends into the slot of the block; means for clamping the end portions of the matrix in the block slot; and means projecting from the oral cavity of the patients mouth when the matrix encircles a tooth for advancing or retracting the block relative to the head; the clamping means also being operable from a position exterior of the patients mouth; the bar being undercut to provide space to allow a wedge to be driven into a position between the tooth having the matrix loop applied thereto and the adjacent tooth.

5. In a dental matrix band retainer: an opensided frame, including a bar having a matrix band-supporting head at one end thereof; the head having a slot extending thereinto from an exposed surface of the head to slidably receive an intermediate portion of a looped matrix band; the head projecting laterally of the bar and being confined to the open side of the frame; a block slidably mounted on the bar and extending laterally thereof on the same side of the bar as the head; the block having a diagonal slot extending thereinto from an exposed surface of the block to receive and closely confine end portions of the matrix band; the slot in the block being arranged on the same side of the bar as the head; thevblock slot extending from a foreward end of the block to an unobstructed face of the block at the open-side of the frame; the slots in the head and block opening toward a common plane and being dimensioned for edgewise insertion of the matrix band thereinto; the open-side of the frame giving free accessfrom above; below and laterally to the portion of the matrix band disposed between the head and block for unobstructed manual grasping and vertical t shifting of said portion by an operator during in- 00 sertion or removal of the band; means for clamping the end portions of the matrix band to the block; and means for advancing and retracting the block relative to the head.

BENJAIVIIN F. TOFF'LEMIRE.

REFERENCES CITED The following references are of record in the file oi' this patent:

UNITED STATES PA'I'ENTS Number Name Date 1,990,381 Ivory Feb. 5. 1935 2,439,708 Tomemire Apr. 13. 1948 7s 

